Simple and inexpensive method for cryopreservation of fish sperm combining straw and powdered dry ice.
Here, we propose a simple and inexpensive method for fish sperm cryopreservation. Sperm samples of the loach Misgurnus anguillicaudatus (Teleostei: Cobitidae) were diluted 7-fold by an extender containing 63.5 mM NaCl, 114 mM KCl, 20 mM Tris and 10% methanol. The cryogenic straws were placed in three kinds of self-made tubes which diameter was changed by commercially available materials and then immersed into powdered dry ice for 2 min and plunged into liquid nitrogen. This procedure resulted in a cooling rate at -421.4 +/- 119.84 (control), -55.8 +/- 4.32 (tube 1), -40.2 +/- 3.43 (tube 2) and -33.3 +/- 2.09 C/min (tube 3). In the slowest cooling rate by the tube 3, total motility (72 +/- 3 %), duration (146 +/- 12 s) and hatching rates (29 +/- 04 %) were higher than those by other rates. Progressive motility (83 +/- 5 %) did not differ significantly from fresh samples.
Yasui
George Shigueki
GS
Graduate School of Fisheries Science, Division of Marine Life Sciences, Laboratory of Aquaculture Genetics and Genomics, Hokkaido University, Hokkaido, Japan. george@fish.hokudai.ac.jp
Arias-Rodriguez
Lenin
L
Fujimoto
Takafumi
T
Arai
Katsutoshi
K
D000818:Animals; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods*; D003531:Cypriniformes; D004367:Dry Ice; D008297:Male; D012662:Semen Preservation / Q000379:methods*; D013081:Sperm Motility
D004367:Dry Ice